AST-1A Lecture Notes - Lecture 12: Solar Minimum, Yohkoh, Photosphere
Document Summary
One spot acts as the n magnetic pole and the other as the s magnetic pole. At the equator, the sun rotates in about 25 days at the poles, the rotation is slower, about once every 30 days. At the poles, the rotation is slower, about once every 30 days. Therefore, the actual length of the solar cycle is 22 years. In a sunspot pair, for 11 years the spots have the n pole first and s pole follows. For the next 11 years the s pole leads and the n pole follows. The chromosphere is a very thin layer of hot, low density gas at a temperature of. 10,000 k. it emits an emission line spectrum. The corona contains a vary rarefied, but very hot gas (temperature of 1-2 million. The corona stretches to about 20 solar radii. Solar wind: low density gases in the corona are hot enough that the gravity of the sun cannot hold onto them.
